基于分布式应变监测的大跨度斜拉桥结构损伤探测  

Damage Detection of Long-span Cable-stayed Bridge Based on the Distributed Strain Monitoring

作　　者：范哲[1] 冯新[1] 周晶[1] 

机构地区：[1]大连理工大学海岸与近海工程国家重点实验室,辽宁大连116024

出　　处：《防灾减灾工程学报》2014年第1期46-50,72,共6页Journal of Disaster Prevention and Mitigation Engineering

基　　金：国家自然科学基金委创新研究群体基金项目(51121005)资助

摘　　要：结构损伤具有典型的局部性质,通常表现为局部应变的异常。结构应变的分布式监测与损伤敏感特征分析,是实现大跨桥梁损伤探测与定位的理想途径之一。但是,由于环境噪声的影响,对分布式应变信号的监测往往不能准确反映结构出现的损伤状况。因此,提出了通过小波变换对分布式光纤测试的斜拉桥桥面应变分布进行多尺度分析的方法。这种方法可以克服分布式光纤应变监测信号受观测噪声和空间分辨率平均效应的不利影响,准确地确定空间域信号奇异点在桥面的位置。同时,在实验室建立了比尺为1∶150的模型斜拉桥。通过对斜拉桥数值模型与物理模型试验结果的分析和比较,验证了所提出方法的有效性。Structural damage is a typical local phenomenon, which commonly leads to the abnor- mality in the local strain. Monitoring the structural damage in a distributed manner, as well as extracting the damage-sensitive feature, is an effective way to detect and position the damages in the long-span bridges. However, monitoring the distributed strain may not truly reflect the dam- age state of the structure due to the effect of environmental noise. Therefore, a multi-scale analy- sis for the distributed strain signal is proposed by wavelet transform. The proposed method alle- viates the noise effects on the strain signals and averaging effect, thus determines the exact loca- tion of the singular point of the spatial signal accurately and conveniently. Meanwhile, a cable- stayed bridge model with scale ratio 1 ： 150 was built in the laboratory. Both of the numerical sim- ulation and model tests were carried out on a cable-stayed bridge model to testify the effectiveness of the proposed method.

关 键 词：小波变换 分布式光纤 桥梁健康监测 损伤识别 斜拉桥模型 

分 类 号：TU352.1[建筑科学—结构工程]